Aquaculture

Rainbow Trout Welfare in Hatchery and Ongrowing Systems

Welfare science for rainbow trout from egg to harvest across freshwater production systems.

Key Facts

Rainbow trout are the most widely farmed salmonid globally after Atlantic salmon
Aggression and dominance hierarchies develop in juveniles
Crowding, handling, and poor water quality cause chronic stress
Slaughter method significantly affects both welfare and product quality

Welfare Considerations

Rainbow trout welfare challenges begin in the hatchery with crowded tanks, fry-to-fry aggression, and handling during grading. Ongrowing welfare is affected by stocking density, water temperature, and oxygen levels. Percussive stunning before slaughter is standard in welfare-certified production. Whole-life welfare approaches from egg to harvest are increasingly adopted.

What You Can Do

Choose rainbow trout with RSPCA Assured or equivalent certification
Support adoption of mandatory stunning at slaughter for all farmed fish
Ask retailers about farm welfare standards for the trout they stock